Organo-metal complexes and lubri-cating oils containing them



States Patent flice 2,721,8 1? Patented Oct. 25, 1955 John F. Palmer, J12, Shrewshury, Mo., assignor to Monsanto Chemical Company, St Louis, Mo, a corporation of Delaware No Drawing. Application April 6, 1953, Serial No. 347,149

19 Claims; Cl. 252-43 particularly this inventionrelates to the oil-soluble organo-metal complexes resulting from the reaction of a di-higheralkyl amine with carbondisulfide and an oil-soluble basic alkaline earth metallo hydrocarbon sulfonate. This invention also relates to mineral oils of lubricating viscosity containing the novel oil-soluble plexes, may be prepared by reacting a'd-ialkyl amine 1 wherein the respective alkyl substituents are higher alkyl radicals, that is alkyl radicals containing at least 5 carbon atoms, with carbon disulfide and an oil-soluble basic alkaline earth metallo hydrocarbonsulfonate. The

new compositions are. particularly useful in lubricating oil compositions which are employed in internal combustion engines used in the operations of automobiles, aircraft and similar vehicles, including-Diesel engines, to improve their operation by preventing or retarding corrosion, piston ring sticking, cylinder wear,- and carbon and varnish formation,

The characteristics of the new organo-metal complexes of this invention vary somewhat depending upon the oil-soluble. basic. alkaline earth metallomhydrocarbon sulfonate reactant as well as upon the (ii-higher alkyl amine reactant. Thusrit isto'becunderstood that this invention is not limited to any theories as to the arrangement of atoms .in' the-.new compositions but pertains broadly tothe organo-metal complex obtained upon react-- ing in substantially.equimoleculan proportions a dialkyl amine wherein the respective alkyl substituents contain at least 5 carbon atoms,- carbon disulfide and an oilsoluble basic alkaline earth. metallo hydrocarbon s'ulfonate;,,' .1 I a a i All oil-soluble basic alkaline earth metallo hydrocarbon sulfonates are contemplated astreactants herein. By alkaline earth metal is meant to include suchdivalent metals as magnesium, calciu'rn strontium and barium. For pur-.

poses of this invention magnesium has been included in the alkaline earth; metal group; The preferred sulfo-.

nates are the oil-soluble basic barium hydrocarbon sulfonates. Theeil-solublebasic alkaline emth metallo su lfonates are prepared in known manner from a hydrocarbon sulfonic {acid of which typical. examples are those sulfonic acids obtainedfrom aromatic hydrocarbons of the benzene series, the naphthalene series-,- the anthracene series, etc., -and their alkylated homologues, and a sulfonatingxagent such as strong. sulfuric acid, oleurn, chlorsulfonic acid and the like. Other typical hydrocarbon sulfonate reactants arethose obtained in known manner from a sulfonic acid obtained by treatment of paraffins, naphthenes, the various petroleum fractions (e. g. parafiinic, naphthene and aromatic fractions) with the aforementioned sulfonating agents. A particularly preferred group of oil-soluble basic metallo hydrocarbon sulfonates are the basic barium salts of long chain alkyl substituted aryl sulfonic acids. These sulfonates are of unknown structure, however, it is possible that they may be represented by one or both of the following formulae:

wherein R is a long chain alkyl substituted aromatic hydrocarbon residue. In the second of the above formulae the colon indicates that the barium contributes both electrons to form a Werner coordination compound. It is to be understood, however, that the above structural formulae are merely those which have been postulated on the basis of analytical results and it is not intended that they in any manner should limit the-scope of the invention. v i 1 The long chain alkyl substituted aryl sulfonic acids employed in making the preferred hydrocarbon sulfonate reactant of this invention may be represented by the formula RSO3H wherein R is a longchain alkyl substituted aromatic hydrocarbon residue. -Among the aromatic hydrocarbon nuclei contemplated are such radicals as phenyl, tolyl, ethylphenyl, cumyl, isobutylphenyl, tert. butylphenyl, xylyl, cymyl, biphenylyl, indenyl, naphthyl, and the like. By a long chain alkyl substituent is meant an alkyl radical containing at least 8 carbon atoms. Although any long chain alkyl substituent is contemplated, it is preferable that the substituent be a wax residue and preferably a wave residue having a chain of 20 to 30 carbon atoms. From a practical standpoint it has been found that the aromatic hydrocarbon nucleus of the sulfonic acids (RSO3H) employed in preparing the preferred reactants of this invention should contain not more than four long chain alkyl substituents. In general, however, thosesulfonic acids .wherein the aromatic hydrocarbon nucleus contains 1-3,

inclusive, long chain alkyl substituents are preferred in the preparation of the reactants of this invention and it is particularly preferred that they contain but two long chain alkyl substituents.

The alkyl substituents of the dialkyl amine reactants of this invention contain at least. 5 carbonatoms, and said substituents may be like or unlike. These amines when employed in accordance with this invention produce compositions which exhibit a high degree of mineral oil solubility. As illustrative of the secondary amine reactants contemplated are di-n-arnyl amine, di-isoamyl amine, di-n-hexyl amine, di-isohexyl amine, N-n-amyl-noctyl amine, di-n-heptyl amine, di-n-octyl amine, di-(Z- ethyl hexyl) amine, di-n-decyl amine, di-n-dodecyl amine, di-n-tetradecyl amine, di-n-hexadecyl amine, etc. The preferred amines are'tho'sewherein the alkyl substituents contain from, 58 carbon atoms. The lower dialkyl amines such as. di-ethyl amine, di-allyl amine, and also the alicyclic secondary amines such. as dicyclohexyl amine for some unknown reason provide complex products which are chemically and/or physically unlike the complexes of this'invention.

,In general the organo-metal complexes of this invention are prepared by intimately mixingsubstantially one molecular proportion'of the dialkyl amine. reactant and substantially one molecular proportion of the oil-soluble basic alkaline earth metallo hydrocarbon sulfonate in an inert organic solvent, adding thereto with agitation substantially one molecular proportion of carbon disulfide and then heating the mixture so obtained to etfect removal of substantially one molecular proportion of water. In those instances wherein it is desirable to isolate the new organo-metal complex it is advantageous to use a volatile solvent such as benzene, toluene, solvent naphtha and the like. However, since the new complexes are highly useful as oil additives it has been found advantageous to prepare them in a suitable mineral oil fraction such as one of lubricating viscosity, and market the resultant composite. In practice, it has been found that the new organo-metal complexes will be present in mineral oil fractions of lubricating viscosity in minor amounts, i. e. less than 50% by weight, sufficient to improve the lubricating characteristics of the mineral oil. When employed with other oil additives, particularly the oil-soluble phosphorizedand sulfurized-dicyclic terpenes, they are employed in amounts ranging from 0.1 to by weight, although amounts of about 0.5 to about 3% by weight are preferred.

As illustrative of the preparation of the new compositions is the following:

EXAMPLE I To a suitable reaction vessel is added and intimately mixed 40.5 parts by weight (substantially 0.218 mol) of di-n-hexyl amine and 600 parts by weight of a 31% by weight petroleum oil solution of a basic barium salt of di-wax alkylated benzene sulfonic acid (substantially 0.218 mol). The temperature is lowered to about 10 C. and 16.7 parts by weight of carbon disulfide is admitted slowly below the surface of the mix. Upon completion of the carbon disulfide addition the temperature of the mix is raised to about 2530 C. and maintained at that temperature for about two hours with constant agitation. Vacuum is then applied and the reaction mixture heated at 100130 C. for about 30 minutes to remove all of the water by-product (approximately 3.9 parts by weight which corresponds to substantially one mol per mol of basic metallo hydrocarbon sulfonate) and any unreacted material. Upon cooling approximately 653 parts by weight of a clear reddish-brown colored solution is obtained assaying approximately 3.20% sulfur, approximately 0.44% nitrogen and approximately 4.60% barium, which corresponds to a weight ratio of nitrogen to sulfur to barium of 0.96:6.95:10. Theoretically the reaction product of equal molecular proportions of the respective reactants would yield a product having a weight ratio of nitrogen to sulfur to barium of 1.02:7:10. The organo-metal complex (approximately 237 parts by weight) upon isolation from the petroleum oil solution is found to be a solid amber-brown substance which although wax-like in appearance readily fractures.

EXAMPLE II To a suitable reaction vessel is added and intimately mixed 46.5 parts by weight (substantially 0.218 mol) of di-n-heptyl amine and 600 parts by weight of a 31% mineral oil (SAE-lO grade motor oil) solution of a basic barium salt of a di-wax alkylated benzene sulfonic acid (substantially 0.218 mol). The temperature is lowered to about 10 C. and 16.7 parts by weight (substantially 0.218 mol) of carbon disulfide is admitted slowly below the surface of the mix. Upon completion of the carbon disulfide addition the temperature of the mix is raised to about 2530 C. and maintained at that temperature for about two hours with constant agitation. Vacuum is then applied and the reaction mixture heated at 100- 130 C. for about 30 minutes to remove all of the Water by-product (approximately 3.9 parts by weight) and any unreacted material. Upon cooling approximately 659 parts by weight of a clear reddish-brown colored solution is obtained assaying approximately 3.04% sulfur, 0.47% nitrogen and 4.64% barium which corresponds to a weight ratio of nitrogen to sulfur to barium of 1.01:6.6: 1.0. Theoretically the weight ratio of nitrogen to sulfur to barium of an equimolecular reaction product of the respective reactants is 1.02:7: 10.

EXAMPLE III To a suitable reaction vessel is added and intimately mixed approximately 17.1 parts by weight (substantially 0.109 mol) of di-n-amyl amine and approximately 600 parts by weight of a 15.5% petroleum oil solution of a basic barium salt of di-wax alkylated benzene sulfonic acid (substantially 0.109 mol). The temperature is lowered to about 0 C. and approximately 8.4 parts by weight of carbon disulfide (substantially 0.109 mol) is admitted slowly below the surface of the mix. Upon completion of the carbon disulfide addition the temperature is raised to 20-25 C. and is maintained there for about two hours. Thereupon vacuum is applied and the reaction mix heated at 130 C. for about 30 minutes. Upon removal of all the water by-product (approximately 2 parts by weight) approximately 623.5 parts by weight of a petroleum oil solution containing about 116 parts by weight of the equimolecular reaction product of di-namyl amine, carbon disulfide and the basic barium salt of di-wax alkylated benzenesulfonic acid is obtained. By analysis the weight ratio of nitrogen to barium is found to be about 1:10.

EXAMPLE IV To a suitable reaction vessel is added and intimately mixed approximately 38.5 parts by weight (substantially 0.109 mol) of a commercial mixture of di-n-octyl amine, di-n-decyl amine, di-n-dodecyl amine, di-n-tetradecyl amine and di-n-hexadecyl amine having an average molecular weight of about 355 and approximately 500 parts by weight of an 18.6% mineral oil solution of a basic barium di-wax alkylated benzene sulfonic acid (substantially 0.109 mol). The temperature is lowered to about 0 C. and approximately 8.4 parts by weight of carbon disulfide (substantially 0.109 mol) is admitted slowly below the surface of the mix. Upon completion of the carbon disulfide addition the temperature is raised to 25-35 C. and is maintained there for about three hours. Thereafter vacuum is applied and the reaction mix is heated at 100-130 C. for about 30 minutes. Upon removal of all the water by-product (approximately 2 parts by weight) approximately 545 parts by weight of a reddish brown mineral oil solution containing about 138 parts by weight of the equimolecular reaction product is obtained.

The new compositions of this invention, particularly those obtained by reacting in substantially equimolecular proportions carbon disulfide, a dialkyl amine wherein the alkyl substituents contain from 5 to 8 carbon atoms, and an oil-soluble basic barium hydrocarbon sulfonate when admixed in a lubricating oil with an oil-soluble phosphorizedand sulfurized-dicyclic terpene provide for a highly efficient and valuable lubricant composition. The concentration of the oil-soluble phosphorizedand sulfurized-dicyclic terpene in such compositions ordinarily will vary from 0.1 to 3% by weight but in general 0.3-1% is satisfactory.

The oil-soluble sulfurizedand phosphorized-dicyclic terpenes referred to above are those obtained by reacting a dicyclic terpene, such as pinene, camphene, fenchene and similar terpenes containing one double bond in the molecule and comprising two ring systems, with a phosphorus sulfide at a temperature of about 100-160 C. While any phosphorus sulfide such as PsSs, P4Se, P453, PzSs, P451, etc., can be employed in the preparation of these reaction products, the preferred reaction products are those obtained employing phosphorus pentasulfide (P285). While the proportions of said reactants will vary depending upon the oil-solubility and oil-improvement properties desired the preferred product isthat obtained by the reaction of aboutone mol ota'phosphorus sulfide, e; gr P285, with about founmols of -a' dicyclic terpene, e. g. pinen'e, at a' reiact-ion: temperature in-the range of about 100-160 C. 1

As exemplary of oil-soluble sulfurizedand phosphorized-dicyclic terpenes and theirpreparation the following is illustrative:

EXAMPLE V A mixture of 245 parts by weight of pinene (substantially 1.8 mols) and 220.5 parts by weight of mineral oil (SAE10 grade motor oil) is charged into a suitable reaction vessel and is heated to 110-115 C. While stirring, 100 parts by weight of phosphorus pentasulfide (substantially 0.45 11101) are added slowly while maintaining the temperature at 110-120 C. The temperature of the mixture is then increased to about 150 C. and stirred at that temperature for one hour. After partial cooling of the reaction mixture there is added a small amount of clay and the mixture filtered. The filtered product is a clear red viscous oil, having a sp. gr. of 1.02 at 15.6/15.6 C., a Saybolt viscosity of 145 at 210 F. and analyzing about 4.7% phosphorus and about 13% sulfur.

As exemplary of the properties of the new lubricating compositions the following compositions are prepared and evaluated in a CRC designation L-4-545 (described on page 394 of the CRC Handbook 1946) engine test for oxidation stability:

Parts by weight Lubricant Composition Product of Example I (wt. ratio otN:S:Ba of0.96:6.95:10). ffg igf on 31% petroleum oil solution of the {0.84 llzasic barium {0.98 organo-metal basic barium salt of di-wax sulionic s alkylated benzene 1.87i1 petroleum As illustrative of other specific oil-soluble basic alkaline earth metallo hydrocarbon sulfonate reactants than basic barium di-wax alkylated benzene sulfonate useful in preparing the novel compositions of this invention are basic barium di-wax alkylated naphthalene sulfonate, basic barium tri-wax alkylated benzene sulfonate, basic magnesium di-wax alkylated benzene sulfonate, basic barium petroleum sulfonate, basic magnesium petroleum sulfonate, basic barium di-dodecyl benzene sulfonate, basic calcium petroleum sulfonate, basic calcium di-wax alkylated benzene sulfonate, and the like.

Although this invention has been described with respect to certain embodiments it is to be understood that it is not so limited and it is to be particularly understood that variations and modifications may be resorted to which are obvious to those skilled in the art without departing from the spirit or scope of this invention.

What is claimed is:

1. As a new composition of matter, the oil-soluble organo-metal complex obtained upon heating, with the elimination of water, substantially equimolecular proportions of an oil-soluble basic alkaline earth metallo bydrocarbon sulfonate, carbon disulfide and a dialkyl amine h e e: bsqtivwlky gr ps at n at least 5 rb n atoms-l l 2. As a new composition of matterfthe oil-soluble organo rnetal complex obtained uponheafing, with the eliminatiqn of water, substantially equimolecular proportions of an oil-soluble basic barium fhydrpcarbon sulfonate, carbon disulfideand a dialkyl amine wherein the respective alkyl groups'contain at least 5 carbon atoms.

3. As a new composition of matter, the oil-soluble organo-metal complex obtained upon heating, with the elimination of water, substantially equimolecular proportions of an oil-soluble basic barium long chain alkyl substituted aryl sulfonate, carbon disulfide and a dialkyl amine wherein the respective alkyl groups contain at least 5 carbon atoms.

4. As a new composition of matter, the oil-soluble organo-metal complex obtained upon heating, with the elimination of water, substantially equimolecular proportions of an oil-soluble basic barium wax alkylated aryl sulfonate, carbon disulfide and a dialkyl amine wherein the respective alkyl groups contain from 5 to 8 carbon atoms.

5. As a new composition of matter, the oil-soluble organo-metal complex obtained upon heating, with the elimination of water, substantially equimolecular proportions of an oil-soluble basic barium di-wax alkylated benzene sulfonate, carbon disulfide and a di-n-alkyl amine wherein the respective alkyl groups contain from 5 to 8 carbon atoms.

6. The oil-soluble product of claim 5 wherein the dialkyl amine is di-n-hexyl amine.

7. The oil-soluble product of claim 5 wherein the dialkyl amine is di-n-heptyl amine.

8. The oil-soluble product of claim 5 wherein the dialkyl amine is di-n-amyl amine.

9. A composition comprising a mineral oil of lubricating viscosity and a minor amount based on the oil of the compound of claim 1.

10. A composition comprising a mineral oil of lubricating viscosity and 0.1 to 10% by weight based on the oil of the compound of claim 2.

11. A composition comprising a mineral oil of lubricating viscosity and 0.5 to 3% by weight based on the oil of the compound of claim 3.

12. A composition comprising a mineral oil of lubricating viscosity and heating the mix to effect the eliminaof the compound of claim 4, and 0.1 to 3% by weight based on the oil of a phosphorizedand sulfurizeddicyclic terpene.

13. A composition comprising a mineral oil of lubricating viscosity, 0.5 to 3% by weight based on the oil of the compound of claim 5', and 0.3 to 1% by weight based on the oil of a phosphorizedand sulfurized-dicyclic terpene.

14. A composition comprising a mineral oil of lubricating viscosity and 0.5 to 3% by weight based on the oil of the compound of claim 6.

15. A composition comprising a mineral oil of lubricating viscosity and 0.5 to 3% by weight based on the oil of the compound of claim 7.

16. In the method of making the composition of claim 1 the step which comprises admixing a dialkyl amine wherein the respective alkyl groups contain at least 5 carbon atoms, carbon disulfide, and an oil-soluble basic alkaline earth metallo hydrocarbon sulfonate in a mineral oil of lubricating viscosity and heating the mix to effect the elimination of water.

17. In the method of making the composition of claim 2 the step which comprises admixing a dialkyl amine wherein the respective alkyl groups contain at least 5 carbon atoms, carbon disulfide and an oil-soluble basic barium hydrocarbon sulfonate in a mineral oil of lubricating viscosity and heating the mix to efiect the elmination of water.

18. In the method of making the composition of claim 4 the step which comprises admixing a dialkyl amine wherein the respective alkyl groups contain from 5 to 8 carbon atoms, carbon disulfide and an oil-soluble basic barium wax alkylated aryl sulfonate in a mineral oil of lubricating viscosity and heating the mix to effect the elimination of water.

19. In the method of making the composition of claim 8 5 the step which comprises admixing a di-n-alkyl amine wherein the respective alkyl groups contain from 5 to 8 carbon atoms, carbon disulfide and an oil-soluble basic barium di-wax alkylated benzene sulfonate in a mineral oil of lubricating viscosity and heating the mix to eflfect the elimination of water.

No references cited. 

1. AS A NEW COMPOSITION OF MATTER, THE OIL-SOLUBLE ORGANO-METAL COMPLEX OBTAINED UPON HEATING, WITH THE ELIMINATION OF WATER, SUBSTANTIALLY EQUIMOLECULAR PROPORTIONS OF AN OIL-SOLUBLE BASIC ALKALINE EARTH METALLO HYDROCARBON SULFONATE, CARBON DISULFIDE AND A DIALKYL AMINE WHEREIN THE RESPECTIVE ALKYL GROUPS CONTAIN AT LEAST 5 CARBON ATOMS.
 9. A COMPOSITION COMPRISING A MINERAL OIL OF LUBRICATING VISCOSITY AND A MINOR AMOUNT BASED ON THE OIL OF THE COMPOUND OF CLAIM
 1. 